Police in Santa Ana are investigating a "sophisticated" marijuana growing operation discovered early Friday after a fire alarm in the building was activated, authorities said.
Orange County Fire Authority firefighters responded to a fire alarm at 7 a.m. in a commercial building in the 1100 block of East 17th Street
When firefighters arrived, five men fled the building -- each in a separate vehicle, the Santa Ana Police Department said.
There was no fire in the building. But there were about 1,600 healthy marijuana plants, police said.
The plants were in varying stages of growth, and cultivating equipment was found at the scene.
Police said the operation, located near a middle school, is under investigation.